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Germline mutations of BRCA1/2 genes cause the predisposition of their carriers to breast or/and ovary cancers (BC or/and OC) during the lifetime. Identification of these mutations is a basis of molecular diagnosis for BC susceptibility. Rapid genotyping technique using microarrays for identification of BRCA1 185delAG, 300TG, 4153delA, 5382insC mutations and 4158 AG sequence variant; BRCA2 695insT and 6174delT mutations; 1100delC mutation in CHEK2 gene was applied for 412 randomly collected breast cancer samples from the central region of European area of Russia. In 25 (6.0%) patients (6.0%) BC was associated with other tumours: OC, cervical cancer, colorectal cancer etc. BRCA1/2 and CHEK2 mutations were found in 33 (8.0%) BC patients. The most frequent mutation was BRCA1 5382insC, occurred in 16 (3.9%) BC patients, and CHEK2 1100delC, revealed in 7 (1.7%) BC patients. An application of diagnostic BC-microarray for genetic testing of BRCA1/2 and CHEK2 founder mutations has been discussed.

State Research Center "GosNIIgenetika", Moscow, 117545 Russia). Association of polymorphic markers Arg72Pro of TP53 gene and T309G of MDM2 gene with risk of non small cell lung cancer has been studied in Russians of Moscow region. We found an association of minor Pro/Pro genotype of polymorphic marker Arg72Pro (OR = 5.46, p = 8 x 10(-6)) and TG genotype of polymorphic marker T309G (OR = 5.57, p = 0.007) with non small cell lung cancer development. We have also showed a strong association of both Pro/Pro and TG genotypes with development of adenocarcinoma (OR = 8.71, p = 3 x 10(-6) and OR = 8.13, p = 0.003) and squamous-cell lung cancer (OR = 4.2, p = 0.001 and OR = 7.02, p = 0.002). We have finally found highly reliable association of combined susceptible genotypes of polymorphic markers Arg72Pro and T309G of TP53 and MDM2 genes with non small cell lung cancer and both its subtypes (OR = 7.9, p = 0.01; OR = 9.12,p = 0.02; OR = 7.31, p = 0.03, respectively).

Somatic mutations in the KRAS gene are important markers of some types of tumors, for example, pancreatic cancer, and may be useful in early diagnostics. A biochip has been developed which allows determining most frequent mutations in 12, 13 and 61 codons of the KRAS gene. To increase the sensitivity of the method and to make possible the analysis of minor fractions of tumor cells in clinical samples the method of blocking a wild type sequence PCR amplification by LNA-oligonucleotides has been used. The product of LNA-clamp PCR was further hybridized with oligonucleotide probes, immobilized on biochip. Biochip was tested with 42 clinical DNA samples from patients with pancreatic cancer, mostly ductal adenocarcinomas. As reference methods, the RFLP analysis and sequencing were used. The developed approach allows detecting somatic mutations in the KRAS gene if the portion of tumor cells with mutation is at least 1% of whole cell population.

The purpose of this study was to investigate informativety and clinical significance of most frequent somatic alterations in K-ras, TP53, CDKN2A, MADH4 and more uncommon mutations in BRCA1, BRCA2, CHEK2 genes, which arise on preinvasive stage in sporadic pancreatic adenocarcinomas (PA), in Russian patients. We examined surgically resected and manually microdissected primary PA tissue samples and samples of normal pancreatic tissue for 37 individuals. K-ras mutations in codon 12 were found in 24 tumors (0.65) and none of normal tissue samples. No mutations were detected in BRCA1(185delAG, 300TG, 4153delA, 4158AG,5382insC), BRCA2 (695insT, 6174delT) and CHEK2 (1100delC) genes. Informativety for allelic loss of three tumor suppressor genes studied had not statistically significant differences: 60% - for TP53 (GDB186817) and CDKN2A (D9S974 + D9S162); and 65.7% - for MADH4 (D18S363 + D18S474) (t = 0.48). Maximal frequency of loss of heterozygosity (LOH) was observed for CDKN2A - 0.95. For TP53 and MADH4 it was 0.62 and 0.70 respectively. The tumors included 80% cases showing LOH on different chromosomal loci. The combination of K-ras mutations (c.12) and LOH at 9p, 17p and 18q resulted in a high informativety of selected molecular markers: 85.7%. Instability of microsatellites was found only in 9% of PA.

Ovarian cancer (OC) is one of the leading cause of cancer death in women. Inherited BRCA1 and BRCA2 mutations strikingly increase OC risk (with lifetime risk estimates ranging at 10-60%). Mutation 1100delC in CHEK2 gene was shown to be associated with breast cancer in women carrying this mutation. Knowledge of the nature and frequency of population-specific mutations in these genes is a critical step in the development of simple and inexpensive diagnostic approaches to DNA analysis. The frequencies of 185delAG, 300TG, 4153delA, 4158AG, 5382insC mutations in BRCA1 gene, 695insT and 6174delT mutations in BRCA2 gene and 1100delC mutation in CHEK2 gene were analyzed using biochips in Russian OC patients. We studied 68 women who received a diagnosis of epithelial OC and 19 women with primary multiple tumors involving the ovaries. The 185delAG, 300TG, 4153delA and 5382insC in BRCA1 gene were identified. The most prevailing mutation was 5382insC in BRCA1 gene (87.5% of all BRCA1 mutations OC patients, 50.0% in patients with primary multiple tumors involving the ovaries). No mutations in BRCA2 and CHEK2 genes were detected.